Fixture for cutting circular pieces



Sept. 29, 1953 E- G. ANDERSON 2,653,633

FIXTURE FOR CUTTING CIRCULAR PIECES Filed June 25, 1947 2 Sheets-Sheet l v a 1 \g E r Q R g x 0 0 Q E t Q Q v w [7, 3

JNVENTOR. EDWARD G. ANDERSON Sept. 29, 1953 E. cs. ANDERSON FIXTURE FOR CUTTING CIRCULAR PIECES 2 Sheets-Sheet 2 Filed June 25, 1947 ATTORNEY Patented Sept. 29, 1953 UNITED STATES PATENT OFFICE FIXTURE FOR CUTTING CIRCULAR PIECES Edward G. Anderson, Philadelphia, Pa. Q

Application June 25, 1947, Serial No. 757,039

3 Claims. (01. 143-171) (Granted under Title 35, U. S. Code (1952),

sec. 266) The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.

This invention pertains to the art of machine tools, and more particularly to power saws. The invention comprises a fixture for holding a workpiece while it is being sawed by the machine, the fixture being operable to saw the workpiece circular.

In the art of bending tubing, it is common prior-art practice to have the tubular piece filled with shot when it is being bent, to prevent the tubing from buckling under the strain of bending it. The ends of the tube are plugged to hold the shot confined therein, wooden plugs being commonly used. The fixture of the disclosed embodiment of the invention is particularly adapted to produce such wooden plugs.

Pursuant to the practice of the invention, the fixture comprises a base which is movable with reference to the tool of the machine tool to locate a workpiece held by the fixture in position for machining it. Work-feeding mechanism is supported by the base. An attachment for the base secures the fixture to the machine tool, and comprises guiding mechanism that directs movement of the base to determine the path of the fixture towards and away from the tool of the machine tool. A stop limits movement of the fixture in the direction towards the tool, thereby to locate the work-feeding mechanism in proper machining position with reference to the tool.

In the case of the invention being for the specific job of sawing work circular, the fixture is adapted for use on a standard power saw having a work-support table. The work-feeding mechanism is a chuck rotatable on the base of the fixture, which rests on the table and holds the chuck with its axis disposed in a predetermined direction to form a predetermined angle with the cutting path of the saw blade. The axis of the chuck is perpendicular to the table and parallel to the path of the saw blade in the specific embodiment disclosed, to cut the workpieces cylindrical. The fixture is slidably movable along the table of the machine tool, and the attachment for the fixture comprises a pivot pin to swing the fixture in a predetermined curved path along the table surface towards the saw blade. A stop limits movement of the fixture to locate the chuck to position the work for the saw blade to make the desired out.

A platen carries the chuck and comprises a center pin projecting from the face of the platen. A chuck head is mounted on a carriage, which is supported by the platen to hold the chuck head opposed to the center pin, in clamping engagement with a workpiece between them. The carriage is movable to traverse the chuck head towards and away from platen for adjusting the chuck to hold different thicknesses of work. A drive for the chuck head rotates the work on the center pin to feed the work to the tool and cut the workpiece circular.

The platen is movable in guideways of the base to position the center pin nearer to or farther away from the saw blade for adjusting the fixture to cut the workpiece to a given desired diameter.

Principles of the present invention, and struc-. ture and operation of apparatus that constitutes one practical embodiment thereof, will be more thoroughly understood from the accompanying drawings. In the drawings- Fig. 1 is a perspective view of a fixture embodying the present invention,

Fig. 2 is a plan view of the fixture of Fig. 1,

Fig. 3 is a side elevation, partly in cross-section taken on line 3--3 of Fig. 2, and

Fig. 4 is a cross sectional elevation taken on line 4-4 of Fig. 3, illustrating particularly the carriage construction.

The fixture of the disclosed embodiment is adapted particularly to be used on a band saw, which, in accordance with usual prior-art practice, comprises the saw blade II, which travels in the direction of the arrow in Fig. 1 through the slot I4 of the table I 5 of the machine.

The fixture comprises the base, illustrated generally at II, which is adapted to slide along the top surface of the table I5. The base comprises the bifurcated member l8, having the arms l9, and the channel pieces 20 and 2|, which are attached each to an arm H! by the bolts 22 in the manner shown. A spacer sleeve 23 is provided for each bolt 22 to hold the channel pieces 20 and 2| the desired distance apart. See Fig. 4. The channel pieces 20 and 2! are elongated to extend beyond the ends 25 of the arms [9, and they thereby provide guideways and a rest for the platen, illustrated generally at 26. Bolts. .22 with a companion spacer sleeve 23 for each, are positioned at intervals along the channel pieces 20 and 2!, to hold them in desired spaced relationship throughout, their lengths. See Fig. 3. A stop member 21 is provided attached to the channel members 20 and 21 interposed between them at their ends, the stop 21 operating to limit movement of the platen 26 along the guldeways provided by the channel pieces 20, 2|. Angle pieces 28 are provided, attached against the outer surfaces of the channel pieces 20, 2| by bolts 22 as shown, to extend the top surface of the platen 26, and to provide guide rails therefore in the base IT.

The platen 26 comprises the top plate 30 and the bottom plate 3|, which are attached to each other held in face-to-face relationship by the screws 32. The side edges of the bottom plate 3| are flanged, as illustrated at 33 in Fig. 4, to provide guiding means which cooperates with the guide rails provided by the angle pieces 28. The platen 26 is adjustable in the guideways formed by angle pieces 28, and longitudinally of the base H, the platen being held in adjusted position by the set screw 34. The bottom plate is slightly offset or stepped, as illustrated at 35 in Fig. 3, to provide clearance between the plates 36 and 3| for clamping the platen 26 in adjusted position in the guideways by operation of the set screw 34.

The angle piece 38 is attached to the base I! adjacent to the platen 26 along the path thereof to provide a scale as illustrated in Fig. 2. The scale on angle piece 38 preferably indicates inches of diameter, and serves to indicate the platen 26 being set for cutting workpieces to predetermined desired diameters.

A work-feeding mechanism is supported by base I1, and comprises the center 40, which projects from the face of the platen 26, and the chuck head 4|, which faces towards the center pin 40, as shown. The center pin a6 is positioned to be coaxial with the chuck head 4|, and the chuck head 4| and center pin 46 cooperate to comprise a chuck which engages and holds workpiece 43 to feed it to the saw blade H, as seen in Fig. 1. Work engaging points 44 project from the face of the chuck head 4| towards the platen 26, and are adapted to be embedded in the workpiece 43. The chuck head 4| is rotatable in the bearing 46 of the bracket 41, the handle or knob 48 being attached to the chuck head 4| at the other end of the bearing 46.

A carriage, indicated generally at 50, supports the bracket 41 and the chuck head 4|, and traverse mechanism for the carriage is operable to adjust the location of the chuck head 4| towards and away from the center pin 46 for different thicknesses of work. The posts guide movement of the carriage 50, and project upwardly from the platen 26, the posts 5| being attached thereto, for example by being riveted to the upper plate 30 as indicated at 52. The cross piece 54 is attached to the upper ends of the posts 5|, and provides a bearing for the lead or traverse screw 55, which is rotatable, for example manually by means of the handle 56. The nut 56 is traversed by rotation of the lead screw 55, the nut 58 supporting the bracket 41 mounted to swing on the pivot 53. The bracket 41 is rotatable on the pivot 53 to swing the chuck head towards and away from the center pin 46, the stop 6| being provided attached to the nut 58 and comprising an abutment to limit movement of the chuck head 4| towards the center pin 40 and to place the face 42 of the chuck head in parallel relationship with the platen 26 in which position the center pin 40 and chuck head 4| are coaxial with each other. The compression spring 62 acts between the abutment 63 projecting upwardly from the nut 58 and the abutment 64 projecting upwardly from the bracket 41 to actuate the bracket to move the chuck head 4| in a direction towards the pin 40 and oppose reverse movement, the movement towards pin 40 being limited by stop 6|.

The fixture of the disclosed embodiment is adapted to accommodate workpieces of various thicknesses within limits determined by the traverse of the lead screw 55. When a workpiece 43 is to be held by the fixture, its material being wood for example, the piece is placed on the platen 26 and pressed against the platen to project the center pin 46 into the material of the piece. Now the lead screw is rotated to advance the chuck head 4| towards the center pin 46 until it engages the surface of the workpiece 43. It is not intended that traverse of the chuck head 4| by means of the lead screw 55 will operate to project the points 44 into the workpiece 43. Instead, the bracket 41 will swing on its pivot 59 against the tension of the spring 62, the lead screw being turned an amount sufiicient to place the face 42 of the chuck head 4| in parallel relationship with the platen 26 when the points 44 become projected into the material of the workpiece 43. The nut 58 having been traversed in the manner described, pressure is now applied to the knob 46 to project the points 44 into the material of the workpiece 43, projection of the points 44 into the workpiece 43 being limited by the stop 6| when the face 42 of the chuck head 4| is in contact with the surface of the workpiece 43 and in parallel relationship with the platen 26. See Fig. 1.

Bevel gear 67 is attached to the chuck head 4|. Bevel gear 68 is provided in mesh with gear 6?, the gear 68 being mounted to rotate in bearing 69, which is supported by the arm 10 attached to the bracket at 41 through the contact plate 1|, Fig. 3. The handle or knob 12 is rotatable manually to rotate the gear 68, and the chuck head 4| through gear 67. The chuck head 4| being in engagement with the workpiece 43 by means of the points 44, rotation of the handle or knob 12 operates to rotate the workpiece 43 on the center pin 46, the workpiece sliding on the surface of the platen 26.

The bifurcated member l6 of the base I! is provided with the pivot pin 15, which constitutes an attachment for securing the fixture in position for operation with the power saw of table If: and blade ll. The bearing bracket 16 is secured to the edge surface 1'! of the table |5 to provide a bearing 18 for the pivot pin 15, the bearing 18 being preferably located with reference to the table IE to be opposite the saw blade H. Projecting laterally from the bifurcated member I8 is the arm 19, which carries the stop pin adapted to abut against the edge surface 11 of the table l5 of the machine. The fixture is adapted to slide along the top surface of the table l5, this being swinging movement around the pivot pin |5. The movement is limited by the stop pin 80 engaging the edge surface ll of the table I5, which locates the center pin 40 approximately in a line between the pivot pin 15 and the saw blade H, as indicated in Fig. 2. The work-feeding mechanism of chuck 46, 4| is thereby located with reference to the saw blade H to hold the workpiece 43 in position to cut it circular.

With a workpiece 43 held chucked between the chuck head 4| and the center pin 40, the fixture is swung on the pivot pin 75 to slide along the surface of the table l5 until the stop pin 60 engages the edge surface 11 of the table |5. This movement has caused the saw blade H to cut into the workpiece from the edge thereof to a position in the circle to be out. Now the knob 72 is turned manually, and this operates to turn the chuck head 4| and the workpiece 43 with it in sliding engagement with the platen 26, the workpiece being thus rotated on the center provided by the pin 40. Turning the workpiece with relationship to the saw blade operates to cut the piece cylindrical, to the contour indicated in Fig. 1. Preparatory to feeding the workpiece 43 to the saw blade H in the manner described, the position of the platen 26 was adjusted, and the platen was secured in adjusted position by the set screw 34. The adjustment was made for cutting the workpiece 43 to the desired diameter, as indicated on the scale of 3B.

The structure shown in the drawing and described in detail hereinbefore is one practical embodiment of the invention. The invention is not limited to the specific structure disclosed, the scope of the invention being determined by the accompanying claims.

What is claimed is:

1. In a chuck construction for holding a workpiece of wood or the like material, a platen, a center pin projecting from the face of the platen, a guideway projecting from the platen, a carriage movable along the guideway, a chuck head supported by the carriage opposed to the center pin, a pivotal mount between the chuck head and the carriage to swing the chuck head into positions towards and away from the center pin, a stop limiting movement of the chuck head relative to the carriage into position towards the center pin with its face disposed parallel to the platen, a spring holding the chuck head resiliently against the stop, and a traverse for the carriage to actuate it along the guideway.

2. A fixture for a power saw embodying a worksupport table, the fixture comprising a base to rest on the table of the saw for the fixture to slide along the table, a work-feeding mechanism supported by the base, an attachment for the base to secure the fixture to the power saw, the

attachment being free to permit the base to slide along the table and comprising guiding mechanism for directing the movement of the base to transmit the work-feeding mechanism towards and away from the saw blade of the power saw,

the work-feeding mechanism comprising a drive independent of the drive of the power saw to feed the work to the saw blade, the work-feeding mechanism comprising a platen carried by the base and a chuck carried by the platen, the chuck comprising a chuck head positioned opposed to the platen and a center pin projecting from the platen towards the chuck head coaxially therewith, the drive of the work-feeding mechanism being connected to the chuck head with reference to the center pin and platen, the support of the work-feeding mechanism by the base comprising a, carriage for the chuck head and traverse mechanism for the carriage projecting away from the platen to adjust the position of the chuck head towards and away from the platen and the center pin, a bracket pivotally mounted to swing on the carriage towards and away from the platen, the chuck head being secured to the bracket in position opposed to the platen, a stop limiting movement of the bracket towards the platen when the chuck head is at a position coaxial with the center pin, a spring tensioned to oppose movement of bracket away from the stop.

3. In combination with a power saw comprising a work-support table, a fixture comprising a base slidable along the table of the saw, a work-feeding mechanism supported by the base, an attachment between the base and the table to secure the fixture to the power saw, the attachment being free to permit the base to slide along the table and comprising guiding mechanism for directing the movement of the base to transmit the work-feeding mechanism towards and away from the saw blade of the power saw, the work-feeding mechanism comprising a drive independent of the drive for the power saw to feed work to the saw blade, the attachment comprising a pivot pin secured to the base, a bearing for the pivot pin secured to the table in position for the workfeeding mechanism to be located in work-feeding position with reference to the saw blade, and a stop limiting movement of the base to hold the work-feeding mechanism located in Work-feeding position.

EDWARD G. ANDERSON,

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 213,222 Mayo Mar. 11, 1879 509,534 Hayne Nov. 28, 1893 429,072 Trethewey May 27, 1890 557,180 Anthon Mar. 31, 1896 967,129 Johnston Aug. 9, 1910 1,543,100 Craig June 23, 1925 1,611,738 Guilford Dec. 21, 1926 1,639,039 Knabusch et al. Aug. 16, 1927 1,866,704 Glaze et al. July 12, 1932 1,881,802 Mattison Oct. 11, 1932 FOREIGN PATENTS Number Country Date 41,798 Switzerland Dec. 4, 1907 51,779 Austria Jan. 25, 1912 

